1. Technical Field
The present disclosure relates to an imaging device, and particularly to an imaging device capable of performing a multiple exposure.
2. Description of the Related Art
Image capturing systems are widely used in the field of consumer goods, industrial goods, and the like. Such image capturing systems typically include imaging devices that perform a single exposure (may be referred to a “typical exposure”) and a single reading during a single frame period. Imaging devices that perform a plurality of exposures and a single reading during a single frame period are also known. The plurality of exposures are typically referred to as a “multiple exposure”. In a multiple exposure, image data that are obtained by sequentially capturing images are superimposed, and the superimposed image data are read as one image data.
Image data obtained with a multiple exposure include information on the change of a subject, such as motion information. In a multiple exposure, an image of a stationary subject, which does not move, such as the background, is captured in the same manner as in a typical exposure. On the other hand, in the case where an image of a moving subject is captured, the change of the moving subject can be reflected on the image data obtained with a multiple exposure. With a multiple exposure, the locus of the motion of the subject can be observed in a single image. In this manner, a multiple exposure is useful for analyzing moving subjects and for analyzing high-speed phenomena.
Japanese Unexamined Patent Application Publication No. 2001-197373 discloses an imaging device capable of capturing images with a multiple exposure (hereinafter referred to as “multiple-exposure imaging”) while changing the exposure period. With the imaging device, a more natural series of images can be obtained at a high dynamic resolution.